TM 9-2320-361-10 2-51. OPERATION OF CARGO BODY ARCTIC KIT (Contd) c. Insulated Body Enclosure. General. The insulated body enclosure (7) protects troops and cargo and retains warm air in arctic conditions. A step assembly is installed for easy access to rear door, Window (8) covers on inside of insulated body enclosure (7) have zippers for easy closing and opening. d. Operation of Lighting System. General. Two dome lights provide illumination for interior of insulated body enclosure (7). Dome lights are operated by switch (9) on inside rear of insulated body enclosure (7). e. Speaking Tube. General. Speaking tube (2) at inside front of insulated body enclosure (7) permits communication between personnel in cab and personnel in cargo body. 2-209